deaf的意思是“聋的；听不见的”。fall on deaf ears可不是“落在了听不见的耳中”，而真实含义是“对...置若罔闻，充耳不闻，没有被听取，未被理睬”。

【例句】
You will go before the council, but your words will fall on deaf ears.
你是可以去议院，但议员们对你的话会充耳不闻。

I reminded him three times that the homework assignment was due but it fell on deaf ears. Now he’s failed!
我提醒了他三次该交家庭作业了，但他当耳旁风，置之不理。这不，他考试不及格。